Timer for explosive engines



Aug. 4, 1925.

' v52 CJEZK JOSIPH J. 0055s.

J J DOBES TIMER FOR EXPLOSIVE ENGINES Filed June l0, 1919 Patented Aug.4, 1925.

UNITED STATES PATENT OFFICE.

:rosnrn J. DOIBES, or CHICAGO, ILLINOIS, AssIGNoR TO THE nnnnsonCOMPANY, A CORPORATION or INDIANA.

TIMER FOR EXPLOSIVE ENGINES.

To all whom it may concern:

Be it known that I, JOSEPH J. Doers, a citizen of the United States,and'resident of Chicago,'in the county of Cook and State of Illinois,have invented certain new and useful Improvements in Timers for EX-plosive Engines; and I do hereby declare that the following descriptionof my invention, taken in connection with the accompanying sheet ofdrawings, forms a full, clear, and exact specification, which willenable others skilled in the art to which the said invention appertainsto make and use the same.

This invention has general reference to timers for explosive engines;and it consists, essentially, in the novel and peculiar combination ofparts and details of construction, as hereinafter first fully set forthand described, and then pointed out in the claims.

The object of this invention is the production of an eiiicient,serviceable, and comparatively inexpensive timer for regulating the timeof explosion of the charges in explosive engines, so that the explosionor ignition of the charges will occur at the proper moment. It is awellknown fact that in order to effect the ignition of the explosivecharges in internal combustion engines at the correct moment, thisignition must take place shortly before the moment when the pistons ofthe engines reach the limit of their compression strokes, and that aminute fraction of time is required to ignite these charges before theybecome efiective. It is, furthermore known that the speed of the enginenecessitates regulation 'of the time when ignition must take place, andthat the faster the engine is working, the earlier the ignition of thecharge must take place.

I11 internal combustion engines of the present day, the ignition of theexplosive charge is eifected'by an electric spark which is derived fromelectric storage batteries, and magnetos, and the proper time when theignition takes place is regulated by what is technically known as atimer, which at the proper moment sends an electric current through aninduction coil to the spark plug where an electric spark is formed inthe spark gap of the latter device.

It is to this class of instruments to which my present inventionappertains, and in the drawings forming a part of this specification, Ihave shown an embodiment of my present invention.

In these drawings Figure l is a front elevation of this timinginstrument. Fig. 2 is'a sectional view on the indirect line 22 ofFig. 1. Fig. 3 is a detached sectional view of the rotor and a portionof its driving shaft taken on the line 33 of Figure 1. Fig. 4 is asectional view on line 44 of Fig. ,1. Fig. 5 is a perspective view ofone of the contact electrodes detached.

Like parts are designated by the same characters and symbols ofreference in all the figures.

The reference numeral 10 in the drawings designates the casing of thistimer. It is, preferably, a cup-shaped steel stamping of circularcontour having a straight rim 12, and a dome-shaped or conical end 13.

This casing is attached or held to the gear casing or crank casing of aninternal combustion engine, in any approved manner, preferably by aresilient bar 14, Fig. 2, pressing upon the casing at the apex of thecone. Into the open end of this casing projec ts the cam shaft 15, whichextends from the crank casing and is connected to the crank shaft bygearing, not shown, but of well-known construction. Upon the outer endof this shaft 15 there is mounted a rotor, consisting of a hub 16, saidhub having an extension 17, to which there is pivotally connected anelectrode 18, by a pin 19, passing through lugs 20, formed on thecontact electrode 18, and through the extension 17. This electrode is acurved, preferably hardened steel blade which has at one end a curvedtail or projection 21, Fig. 1, which bears againstthe extension 17. Inthis protuberance there is a bore 22, and in this bore there is a lightcoil spring 23, which bears against the under side of the curvedelectrode 18, and forces the tail'21 against the extension 17 andthereby preknown Ford automobiles, is, nevertheless adapted foremployment on other explosiveengines; and while, as shown, it is adaptedfor use on four-cylinder engines, it is capable of being installed inmotors having a greater or lesser number of cylinders, as willhereinafter appear.

The rim of the casing 10 is punctured by four screw-holes placed 90degrees apart, thus dividing the easing into four equal portions. Inthese screw holes there are placed, preferably, machine screws 25,having their heads within the casing. To each of these screws 25 thereis connected an electrode, which consists of a hardened steel bladeshaped to arcuate form, as at 26, and then by a close return bend 27 toa straight portion 28, which has a slotted aperture 29, by which it ispassed over the screw 25.

Between the straight portion 28 and the inner surface of the casingwall, there is placed a washer 30; and between the outer surface of thecasing and the nut 31 on the screw 25, there is another washer 32, allof which washers are, preferably, made of a slightly elastic materialwhich is not a con ductor of electricity, to insulate the electrodesfrom the timer casing.

To the screws 25 there are connected the usual electric conductors 33,that connect the electrodes, by way of the induction coil, to the sparkplugs of the motor.

Attention is now invited to the electrodes, the curved portions 26 ofwhich are spaced a certain distance from the center of the shaft 15, andthe electrode 18, the curved member of which is spaced from the centerof the shaft a distance slightly in excess of that of the electrodes 26when the electrode 18 is in outwardly extended position. It follows thatwhen the rotor revolves and the electrode 18 thereof approaches anelectrode 26, the electrode 18 will be slightly depressed and its coilspring compressed, so that the two electrodes 18 and 26 will be inpositive netallic contact and slide upon each other, and that by theelectrode 18 sweeping over the electrode 26, both electrodes will be atall times kept perfectly clean and free from any deposit of dirt, andother foreign matter that might reach and gather in the interior of thecasing 10.

It will be seen that the slight resiliency of the insulating washers 30and 32 and also any slight resilency in the me tallic members 26 willtend to the production of a sharp break in the current as the movableelectrode leaves any one of the fixed electrodes, thereby preventingarcing-and producing a hotter spark at the plug, due to a well knownprinciple of the induction coil.

I have hereinbefore mentioned that the electrodes have the slottedportions 28. This slotting of the electrodes permits of a lateralmovement thereof, so that the exact point of making contact with theelectrode 26 can be adjustably attained which is necessary to cause themotor to function properly.

To the casing 10 there is secured a lug 34, Fig. 1, by which, and a rod35, connected to the lug by a pivot 36, the casing can be oscillated sothat rotating it in one direction, the moment of contact of theelectrodes will be advanced, while a movement in the opposite directionwill retard or delay the time of making contact to close the electriccircuit, it being understood that the establishing of contact of theelectrodes depends upon the rotative speed of the motor, and must beadvanced as the speed of the motor increases.

In order to connect the rotor to the shaft 15, there is formed at theinner end of the hub 16, a slot 37, Fig. 3, and near the end of shaft15, there is inserted a pin 38, a cap 39 being placed over the end ofsaid hub to retain the pin 38 in position.

The inner end of the shaft 15 is reduced in diameter and the reducedportion is ex ternally screw-threaded to receive a locking nut 40. whichholds the cap 39 to the shaft 15. This, however, does not lock the rotorto the said shaft, so that the rotor can be readily removed from theshaft when desired or found necessary, in an obvious manner.

As hereinbefore stated, the timer described is adapted for use onfour-cylinder explosive engines. To enable this timer being employed ontwo-cylinder engines, all that is required is to remove twodiametrically opposed contact electrodes: while for a three cylinderengine, three of these electrodes are used and then arranged 120 degreesapart. For an engine having more than four cylinders, the casing 10 willbe correspondingly enlarged and the proper number of contact electrodesand their accessories installed therein.

It may finally be observed that the rotor with its single curvedelectrode 18, in conjunction with the curvature of the electrodes, iscapable of rotating in forward and backward directions, so that thetimer will correctly function whether the engine rotates in a forward orbackward direction.

I have hereinbefore described the preferred embodiment of my invention,but I desire it to be understood that I am aware that changes in thedetails of construction may be made without departing from the scope ofmy invention as defined in the appended claims.

Having thus fully described this invenesa-e67 tion, I claim as new, anddesire. to secure to myself by Letters Patent of the United States v 1;A timer for internal combustion engines, comprising, in combination, acasing. a multiplicity of electrodes in said casing, each of saidelectrodes being a substantially U-shaped blade, one of the limbs ofsaid blade being arcuate, the convex side of the blade being in thedirection of the center of the casing, the other limb of said U-shapedblade being slotted, a screw in each of said slots to secure saidelectrodes to the inner wall of said casing, a shaft in said casing andextending therefrom to connect with the aforesaid engine, a rotorremovably connected to said shaft, said rotor having an extension, anelectrode or brush pivotally connected to said extension, said brushbeing a curved blade the convex side of which is in the direction of thebefore-mentioned electrodes, said brush having means to limit itsoutward movement, and a spring in said extension and acting upon saidbrush to support it in outwardly extended position.

2. A timer for internal combustion engines, comprising, in combination,a casing, a multiplicity of electrodes in said casing, each of saidelectrodes being a substantially U-shaped element, one of the limbs ofsaid element being decidedly curved, the convex side of the curve beingin the direction of the axial line of said casing, the other limb ofsaid element being slotted, a screw in said slot for securing saidelement to the inner surface of said casing, there being insulatingwashers upon each screw to insulate said U-shaped electrodes from saidcasing, a shaft in said casing and projecting therefrom to connect withthe aforesaid engine, a rotor removably secured to said shaft, saidrotor having an extension, an electrode or brush pivotally connected toa said extension, said brush being an arcuate blade, the convex side ofwhich is in the direction of the said U-shaped electrodes, said brushhaving a tail constructed to contact with said extension to limit theoutward movement of said brush, a spring in said extension and actingupon said brush to support it in outwardly extended position, and meansfor oscillating said casing.

3. A. timer including a casing, a plurality of contact-s on the casing,a rotary shaft disposed centrally of the casing and having a contactmember to cooperate with the first mentioned contacts on the casing, thecontact member on the rotary shaft comprising a continuous rigid metalplate pivotally connected at one end to said shaft, a portion of theplate being adapted to contact with the first mentioned contacts, andresilient means for pressing the outer contact portion of said contactmem ber outwardly, and each of the contact members onthecasingconsisting of a s ingle continuous substantially rigid metalplate having a' base portion at one end thereof secured to the casing,an intermediate outstanding part, and an outer contact portion disposedat an angle to said out standing part and spaced from said base portion,whereby a firm support for the said outer contact portion is affordedwhile providing for slight cushioning thereof to pre vent reboundingupon impact of the rotary contact member therewith.

4. A timer including a casing, a plurality of contacts on the casing, arotary shaft disposed centrally of the casing and having a contactmember to cooperate with the first mentioned contacts on the casing; thecontact member on the rotary shaft comprising a continuous rigid metalplate pivotally connected at one end to said shaft, a portion of theplate being adapted to contact with the first mentioned contacts, andresilient means for pressnig the outer contact portion of said contactmember outwardly, and each of the contact members on the casing being ofgeneral U-shape form constructed from a single continuous substantiallyrigid metal plate and comprising a base portion at one end thereoffixedly secured to the casing, an intermediate outstanding part, and anouter contact portion disposed at an angle to said outstanding part andspaced from said base portion, whereby a firm support for the said outercontact portion is afforded while providing for slight cushioningthereof to prevent rebounding upon impact of the rotary contact membertherewith.

5. A timer including a casing, a plurality of contact members on thecasing; a rotary shaft disposed centrally of the casing and having acontact member to cooperate with the first mentioned contacts on thecasing; the contact member on the rotary shaft comprising a continuousrigid metal plate pivotally connected at one end to said shaft andhaving an outer curved contact portion, and resilient means for pressingthe outer contact ortion of said contact member outward y, and each ofthe contact members on the casing consisting of a single continuoussubstantially rigid metal plate having a base portion at one end thereoffixedly secured to the casing, an intermediate outstanding part, and anouter curved contact portion disposed at an angle to said outstandingpart and spaced from said base portion.

6. A timer including a casing, a plurality of contacts on the casing, arotary shaft disposed centrally of the casing and having a contactmember to cooperate with the first mentioned contacts on the casing, thecontact member on the rotary shaft comprising a rigid metal platepivotally connected at one end to said shaft, and resilient means forpressing the outer part of said contact member outwardly, and each ofthe contact members on the casing consisting of a single continuoussubstantially rigid metal strip having a base portion at one end thereofsecured to the casing, an intermediate outstanding part, and an outercontact portion spaced from said base portion, Whereby a firm supportfor the said outer contact portion is afforded While providing forslight cushioning thereof to prevent rebounding upon impact of therotary contact member therewith.

In testimony that I claim the foregoing as my invention, I have hereuntoset my hand.

JOSEPH J. DOBES.

